Agree with the other answers. Most likely the solenoid. You can buy direct from the manurfacturer or arrange for a fixed price service by ringing 0844 571 5000
Rob, June 2010
solenoid valve diaphragm is failing or grit in it causing to not to shut fully.
retail at about £35
hi-spec plumbing & heating (essex), June 2010
sounds like the solenoid may be jammed, or the heater tank scaled up, if it is the tank then you need a new shower, if it is the solenoid they can be obtained from National shower spares. www.showerspares.com tel
0845 126 4141
